ROME -- The word 'cure' -- long a taboo in HIV/AIDS circles -- is being bandied about freely here at the 2011 meeting of the International AIDS Society.

ROME -- The word 'cure' -- long a taboo in HIV/AIDS circles -- is being bandied about freely here at the 2011 meeting of the International AIDS Society.

The word has been used in symposia, satellite meetings, and even a formal "Rome Statement for an HIV Cure" launched by the society and backed by a who's who of scientists, research organizations, and activists.

It is "the right time to accelerate research on an HIV cure," said Françoise Barré-Sinoussi, PhD, of France's Pasteur Institute in Paris.

Barré-Sinoussi has rock-star status on the scientific side of the HIV/AIDS community. She is president-elect of the AIDS Society and shared the 2008 Nobel Prize in medicine for identifying the human immunodeficiency virus.

She is co-chairing a scientific working group of some 40 people whose goal is to chart a research path to guide future study. The group, which has support from the NIH, the French AIDS research agency, and the Treatment Action Group among others, hopes to have that pathway mapped by the 2012 International AIDS Conference in Washington.

"We know it is possible" to achieve a cure, Barré-Sinoussi told MedPage Today, because it has been done. The so-called "Berlin patient" -- a man with HIV who had bone marrow transplants to treat leukemia -- appears now to be free of the virus.

The Proof of Concept

The case is exceptional, Barré-Sinoussi conceded, and can't be translated into large-scale action. Among other things, the risks and costs of a bone marrow transplant are extremely high. And the donated marrow has to include cells with a specific and rare mutation, the delta32 deletion on the gene that codes for the T-cell receptor CCR5.

People with two copies of that mutation are naturally resistant to HIV infection, because the CCR5 receptor is the main doorway HIV uses to enter its target immune cells. In essence, the Berlin patient -- 45-year-old Timothy Ray Brown -- now has an immune system with innate resistance to the virus.

So far, researchers have not been able to duplicate that feat, but Barré-Sinoussi said the case still might hold some answers. "This is a proof of concept, but what is interesting for me ... is to try to understand the mechanisms," she told reporters.

Researchers are buoyed by that example, as well as by recent studies showing that it may be possible to modify stem cells in order to produce T cells with the delta32 deletion. That opens up the possibility of gene therapeutic approach to a cure.

But Barré-Sinoussi also noted that so-called "elite controllers" provide examples of natural resistance to HIV after infection. For reasons that remain unclear, these patients have detectable HIV, but at low levels, and the virus does not carry on to destroy the immune system even though they are not treated with anti-retroviral drugs.

If that can be duplicated, it would be a so-called "functional cure," Barré-Sinoussi said, and would allow patients to live without anti-HIV medication.

"If it exists naturally, we should be able to reproduce it," she told MedPage Today.

"We are all very optimistic that a remission -- a functional cure -- will be possible," Barré-Sinoussi said. Such a remission would mean that a patient could stop treatment and would also have implications for prevention, since he or she would no longer transmit the virus, she said.

Barré-Sinoussi is not alone in her optimism. The scientific working group that has signed on includes such well-known U.S. clinician-researchers as John Mellors, MD, of the University of Pittsburgh, Martin Markowitz, MD, of New York's Aaron Diamond AIDS Research Center, and Steven Deeks, MD, of the University of California San Francisco.

"We know it's possible, so what we need to do it pursue and get it done," said Rowena Johnston, PhD, of the New York-based advocacy group amfAR, which is also supporting the cure statement.

These Are Early Days

In essence, what has been proposed here is a proposal to develop a road map to a scientific strategy. Actual research proposals -- let alone research -- will have to wait and in any case will be dependent on international agreements both that a cure is possible and that there's money to support study that could last for several decades.

Aside from the purely scientific questions, researchers will have to take into account the ethics of conducting clinical trials of possible cures among people whose HIV may be controlled by currently available treatment, said Mark Harrington of the New York-based Treatment Action Group, one of the organizations supporting the Rome statement.

There will be a "lot of failed trials along the way," he said, and many participants -- even in trials that yield important scientific information -- "will not obtain any benefit."

Experts here were reluctant to estimate how long it will take, with the exception of Johnston, who said we will see an HIV cure "in our lifetime."

The HIV/AIDS community has been here before, of course. In the wake of the remarkable success of the first trials of triple-drug cocktails in the mid-1990s, there was a wave of hope that the medications would eradicate the virus.

Those hopes were dashed in short order because -- as is now known -- HIV has a remarkable ability to hide from drugs in so-called "reservoirs." When treatment is stopped, latent HIV from those reservoirs begins to replicate and the downward spiral of the immune system resumes.

That's a tough trick to overcome, Barré-Sinoussi said. "It will be difficult to reach all the cells that carry the latent virus in all the compartments of the body, for sure," she told MedPage Today, although, in the last analysis, that's what is needed.

But the main obstacle to success would be lack of willpower, according to Harrington.

The only insurmountable roadblock, he told MedPage Today, would be "if we don't try."

Accessibility Statement

At MedPage Today, we are committed to ensuring that individuals with disabilities can access all of the content offered by MedPage Today through our website and other properties. If you are having trouble accessing www.medpagetoday.com, MedPageToday's mobile apps, please email legal@ziffdavis.com for assistance. Please put "ADA Inquiry" in the subject line of your email.